ABSTRACT
Leptospirosis is a widespread zoonosis in the world and is more prevalent in tropical and temperate regions. Flat area of Guilan province is the only endemic area of human leptospirosis in Iran. In 2005, a study was done to investigate the incidence of leptospirosis in the area. We collected blood samples from patients who attended three big general hospitals in the region with clinical presentation consistent with leptospirosis. All sera were examined by a quantitative Igm-Elisa and also by the Microscopic Agglutination Test [MAT] by using 18 standard strains. Sera which were positive in quantitative 19m-Elisa and had titers =160 against at least one pathogenic serovar in mat, were regarded as positive cases [170 from 482]. Analysis of demographic and epidemiological data of positive cases showed that leptospirosis is a disease of predominantly males [62.50%], occurring in high incidence in villagers [89.50%], mainly during the warm season [100%] and notably in September [42.90%]. In addition it is an occupational disease affecting mainly rice field workers [about 90%]